It is interesting that there you are not finding much in way of Marxist criticism on Woolf's work. Perhaps, examining sites where pdf versions of papers written on the topic and then examining those footnotes might be a way to help in this. It seems to me that there could be much Marxist criticism available in Woolf's work. The idea that Mrs. Dalloway is preparing this party for the upper class, whose socially constructed ways of repression and denial of voice is a reflection of the protected world of wealth and privilege. The individuals in this setting are the same who frown on mental illness concerns and deny the full expression of women's voice and those who wish to express feelings towards others that might be perceived as "socially unacceptable." The need of having to conform to a social order predicated on wealth and privilege is the exact condition to which Woolf brings attention. This is a Marxist criticism in so far as it reflects how material wealth and social privilege is not something that individuals control, but rather controls them.
Akannan is absolutely right. May I add something more, if you please? thanks: Many Marxist and Leninist works are based on the concept of Imperialism. A parallel can be easily drawn here, if you consider the period of time Mrs. Dalloway lives. After the first World War, many things changed in the commonwealth and colonies gained more power, which weakened the Empire (you might want to check the reasons of this (economic ones for instance)). Also Imperialism means the domination of one nation among others, which was the case with India, where Peter Walsh lived. While Peter is proud of the level of "civilization" UK achieved, Clarissa feels the opposite way. The Empire is also flawed in the eyes of Septimus, who fought for it during the war, but he does not know the reason why he fought. Septimus fought for his country but his country failed him.